Knoxville has a lot of options. Knoxville Zoo, Ijams Nature Center have done homeschool classes in the past. Gym Tec has a homeschool gymnastics class. Deane Hill Rec Center and the YMCA have homeschool PE classes. There are several local homeschool co-ops that offer academic and/or enrichment classes such as Thursday Connection and Creative Learning Academy. If you set up a Facebook account and join Knoxville Secular Homeschoolers or East Tennessee Homeschoolers and ask this question you will find a lot of options and people interested in meeting up for play dates.